/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.update;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.concurrent.atomic.AtomicLong;

import org.apache.lucene.codecs.Codec;
import org.apache.lucene.index.IndexDeletionPolicy;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.InfoStream;
import org.apache.lucene.util.PrintStreamInfoStream;
import org.apache.solr.core.DirectoryFactory;
import org.apache.solr.schema.IndexSchema;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * An IndexWriter that is configured via Solr config mechanisms.
 * 
 * @since solr 0.9
 */

public class SolrIndexWriter extends IndexWriter {
	private static Logger log = LoggerFactory.getLogger(SolrIndexWriter.class);
	// These should *only* be used for debugging or monitoring purposes
	public static final AtomicLong numOpens = new AtomicLong();
	public static final AtomicLong numCloses = new AtomicLong();

	/**
	 * Stored into each Lucene commit to record the System.currentTimeMillis()
	 * when commit was called.
	 */
	public static final String COMMIT_TIME_MSEC_KEY = "commitTimeMSec";

	String name;
	private DirectoryFactory directoryFactory;

	public static SolrIndexWriter create(String name, String path,
			DirectoryFactory directoryFactory, boolean create,
			IndexSchema schema, SolrIndexConfig config,
			IndexDeletionPolicy delPolicy, Codec codec,
			boolean forceNewDirectory) throws IOException {

		SolrIndexWriter w = null;
		final Directory d = directoryFactory.get(path, config.lockType,
				forceNewDirectory);
		try {
			w = new SolrIndexWriter(name, path, d, create, schema, config,
					delPolicy, codec, forceNewDirectory);
			w.setDirectoryFactory(directoryFactory);
			return w;
		} finally {
			if (null == w && null != d) {
				directoryFactory.doneWithDirectory(d);
				directoryFactory.release(d);
			}
		}
	}

	private SolrIndexWriter(String name, String path, Directory directory,
			boolean create, IndexSchema schema, SolrIndexConfig config,
			IndexDeletionPolicy delPolicy, Codec codec,
			boolean forceNewDirectory) throws IOException {
		super(directory, config
				.toIndexWriterConfig(schema)
				.setOpenMode(
						create ? IndexWriterConfig.OpenMode.CREATE
								: IndexWriterConfig.OpenMode.APPEND)
				.setIndexDeletionPolicy(delPolicy).setCodec(codec)
				.setInfoStream(toInfoStream(config)));
		log.debug("Opened Writer " + name);
		this.name = name;
		numOpens.incrementAndGet();
	}

	private void setDirectoryFactory(DirectoryFactory factory) {
		this.directoryFactory = factory;
	}

	private static InfoStream toInfoStream(SolrIndexConfig config)
			throws IOException {
		String infoStreamFile = config.infoStreamFile;
		if (infoStreamFile != null) {
			File f = new File(infoStreamFile);
			File parent = f.getParentFile();
			if (parent != null)
				parent.mkdirs();
			FileOutputStream fos = new FileOutputStream(f, true);
			return new PrintStreamInfoStream(
					new PrintStream(fos, true, "UTF-8"));
		} else {
			return InfoStream.NO_OUTPUT;
		}
	}

	/**
	 * use DocumentBuilder now... private final void addField(Document doc,
	 * String name, String val) { SchemaField ftype = schema.getField(name);
	 * <p/>
	 * // we don't check for a null val ourselves because a solr.FieldType //
	 * might actually want to map it to something. If createField() // returns
	 * null, then we don't store the field.
	 * <p/>
	 * Field field = ftype.createField(val, boost); if (field != null)
	 * doc.add(field); }
	 * <p/>
	 * <p/>
	 * public void addRecord(String[] fieldNames, String[] fieldValues) throws
	 * IOException { Document doc = new Document(); for (int i=0;
	 * i<fieldNames.length; i++) { String name = fieldNames[i]; String val =
	 * fieldNames[i];
	 * <p/>
	 * // first null is end of list. client can reuse arrays if they want // and
	 * just write a single null if there is unused space. if (name==null) break;
	 * <p/>
	 * addField(doc,name,val); } addDocument(doc); } ****
	 */
	private volatile boolean isClosed = false;

	@Override
	public void close() throws IOException {
		log.debug("Closing Writer " + name);
		Directory directory = getDirectory();
		final InfoStream infoStream = isClosed ? null : getConfig()
				.getInfoStream();
		try {
			super.close();
		} finally {
			if (infoStream != null) {
				infoStream.close();
			}

			isClosed = true;

			directoryFactory.release(directory);

			numCloses.incrementAndGet();
		}
	}

	@Override
	public void rollback() throws IOException {
		try {
			super.rollback();
		} finally {
			isClosed = true;
			directoryFactory.release(getDirectory());
			numCloses.incrementAndGet();
		}
	}

	@Override
	protected void finalize() throws Throwable {
		try {
			if (!isClosed) {
				assert false : "SolrIndexWriter was not closed prior to finalize()";
				log.error("SolrIndexWriter was not closed prior to finalize(), indicates a bug -- POSSIBLE RESOURCE LEAK!!!");
				close();
			}
		} finally {
			super.finalize();
		}

	}
}
